Android Question Install error b4a


Deleted member 114895

Hi to all, I'am new and I have installed b4a in Windows 10 PC.
After Click on Open Sdk Manager button and install all nedeed and checked package I have this messag at end of install :

WARNING: An illegal reflective access operation has occurred

WARNING: Illegal reflective access by com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1 (file:/C:/android/tools/bin/jaxb-impl-2.1.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int)

WARNING: Please consider reporting this to the maintainers of com.sun.xml.bind.v2.runtime.reflect.opt.Injector$1

WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations

WARNING: All illegal access operations will be denied in a future release

Warning: File C:\Users\juanjo\.android\repositories.cfg could not be loaded.

Can you help me to say what are this problem ?
Last 2 questions is : 1.Can I download openjdk version 12 and use this with b4a?
2.Is the openjdk free of charge(not pay royaltis to oracle) ?

Thanks and sorry for my bad English translated.


Licensed User
Longtime User
1. No. You should use Java 8 or 11 for now. Note that you need to use B4A 9.01+ for java 11.
You can find the instructions here:

2. Yes, it is free.

The last warning you can ignore. For the others you need to wait for another answer.
Last edited:
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Deleted member 114895

Thanks for your help in 1 and 2 questions DonManfred.
After install all was I need to start with b4a, I have Warnings, can you say me what Is the problem?
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